(1) Field of the Invention
The present invention relates to the treatment of insulin related diseases, obesity, diabetes mellitus, hyperglycemia, lipid disorders, hyperlipidemia, or low HDL, hypercholesterolemia, hyperglyceridemia, dyslipidemia, and atherosclerosis. The present invention particularly relates to a method which uses anthocyanins, anthocyanidins, ursolic acid and betulinic acid. The invention particularly relates to Cornus spp. fruit extracts as well as other fruits containing these compounds, such as cherries and berries, or mixtures thereof to increase insulin production by cells in vivo. The present invention also particularly relates to compositions to be used in the method for producing the increase in production of the insulin in vivo in the treatment of the related diseases. The present invention also particularly relates to compositions used to prevent obesity and lowering cholesterol and body weight.
(2) Description of the Related Art
The function of insulin is to maintain normal blood glucose levels either by suppression of glucose output from liver or by the stimulation of glucose uptake and its metabolism (Ross, S. A.; Gulve, E. A.; Wang, M. Chemistry and Biochemistry of diabetes. Chem. Rev. 2004, 104, 1255-1282). Insufficient release of insulin or loss of insulin action at target tissues causes aberrant glucose and lipid metabolism. This results in elevated glucose levels in the blood, a hallmark of diabetes (Jovanovic, L.; Gondos, B. Type-2 diabetes: The epidemic of new millennium. Ann. Clin. Lab. Sci. 1999, 29, 33-42). There are two types of diabetes, type-1 (insulin-dependent diabetes) and type-2 diabetes (non-insulin-dependent diabetes). Type-1 diabetes results from autoimmune destruction or inhibition of pancreatic β-cells, the cells that secrete insulin, which leads into insulin insufficiency. Type-2 diabetes is more prevalent and is caused by the inability of β-cells to secrete sufficient amounts of insulin to overcome insulin resistance established by genetic and environmental factors (Henquin, J. C. Triggering and amplifying pathways of regulation of insulin secretion by glucose. Diabetes 2000, 49, 1751-1760). The insulin resistance is a disorder in which insulin inadequately stimulates glucose transport in skeletal muscle and fat and inadequately suppresses hepatic glucose production. The mechanisms involved that prevent the β-cell from secreting sufficient amounts of insulin to overcome peripheral insulin resistance remain to be established.
Oral hypoglycemic agents that directly stimulate insulin release from β-cells (e.g. sulfonylurea based drugs as exemplified by U.S. Pat. No. 6,852,738 to Jones et al, incorporated herein by reference), however, have shown that insulin secretion from islets of type-2 diabetic patients can be elevated sufficiently to overcome peripheral insulin resistance and normalize blood glucose levels. One of the disadvantages of using sulfonylurea-based drugs is that they fail to control normal blood glucose levels (Pfeiffer, A. F. H. Oral hypoglycemic agents: Sulfonylureas and meglitinides. In B. J. Goldstein, D. Müller-Wieland (Eds.), Text book of Type-2 Diabetes. Martin Dunitz Ltd., London, 2003, pp. 77-85). These drugs also adversely affect the ability of β-cells to secrete insulin and cause weight gain (Pfeiffer, A. F. H. Oral hypoglycemic agents: Sulfonylureas and meglitinides. In B. J. Goldstein, D. Müller-Wieland (Eds.), Text book of Type-2 Diabetes. Martin Dunitz Ltd., London, 2003, pp. 77-85). Hence, there is a role for dietary constituents that can regulate blood glucose level or induce insulin production by pancreatic β-cell in addition to traditional ethical drug treatment.
Reports indicate that consumption of fruits and vegetables, especially rich in polyphenols, decreased the incidence of type-2 diabetes (Anderson, R. A.; Polansky, M. M., Tea Enhanced Insulin Activity. J. Agric. Food Chem. 2002, 50, 7182-7186; Anderson, R. A.; Broadhurst, C. L.; Polansky, M. M.; Schmidt, W. F.; Khan, A.; Flanagan, V. P.; Schoene, N. W.; Graves, D. J. Isolation and Characterization of Polyphenol Type-A Polymers from Cinnamon with Insulin-like Biological Activity. J. Agric. Food Chem. 2004, 52, 65-70; Landrault, N.; Poucheret, P.; Azay, J.; Krosniak, M.; Gasc, F.; Jenin, C.; Cros, G.; Teissedre, P. Effect of a Polyphenols-Enriched Chardonnay White Wine in Diabetic Rats. J. Agric. Food Chem. 2003, 51, 311-318). Also, it is known that dietary antioxidants protect pancreatic β-cells from glucose-induced oxidative stress. Anthocyanins are abundant in fruits, vegetables and processed food products such as wine, cider and tea. However, little is known of its ability to reduce or prevent diabetes.
Also, anthocyanins are nontoxic and reported to possess antioxidant, anti-inflammatory and anticancer activities (Wang, H., Nair, M. G., Strasburg, G. M., Chang, Y., Booren, A. M. Gray, J. I., and DeWitt, D. L. (1999) Antioxidant and anti-inflammatory activities of anthocyanins and their aglycon, cyanidin, from tart cherries. J. Nat. Prod. 62, 294-296; Tall, J. M., Seeram, N. P., Zhao, C., Nair, M. G., Meyer, R. A., and Raja, S. N. (2004) Tart cherry anthocyanins suppress inflammation-induced pain behavior in rat. Behav. Brain Res. 153, 181-188; Kang, S., Seeram, N. P., Nair, M. G., and Bourquin, L. D. (2003) Tart cherry anthocyanins inhibit tumor development in ApcMin mice and reduce proliferation of human colon cancer cells. Canc. Lett. 194, 13-19; Zhang, Y., Vareed, S. K., and Nair, M. G. (2005) Human tumor cell growth inhibition by nontoxic anthocyanidins, the pigments in fruits and vegetables. Life Sci. 76, 1465-1472.).
The bioactive natural products present in vegetables, fruits and herbs have generated considerable interest in prevention and treatment of human degenerative disorders like cancer, diabetes and cardiovascular diseases. For example, nuts, whole grains, fruits, and vegetables are rich source of antioxidants such as polyphenols, terpenoids and pigments and these compounds have been associated with the amelioration of several disease conditions. Similarly, phytochemicals present in garlic, soybeans, cabbage, ginger, licorice, and the umbelliferous vegetables are known to possess anticancer activity (Rui, H. L. (2004) Potential synergy of phytochemicals in cancer prevention: mechanism of action. J. Nutr. 134, 3479S-3485S). Also, the polyphenols present in tea are reported to possess anti-diabetic properties (Vanessa, C., and Gary, W. (2004) A review of the health effects of green tea catechins in in vivo animal models. J. Nutr. 134, 3431S-3440S and Mary E. W., Xiaohui, L. W., Brian, K. L., Robert K. H., Masao, N., and Daryl K. G. (2002) Epigallocatechin gallate, a constituent of green tea, represses hepatic glucose production. J. Biol. Chem. 277, 34933-34940.).
The consumption of a diet low in fat and rich in antioxidants reduces the risk of obesity and insulin resistance (Blakely, S.; Herbert, A.; Collins, M.; Jenkins, M.; Mitchell, G.; Grundel, E.; O'Neill, K. R.; Khachik, F. Lutein interacts with ascorbic acid more frequently than with α-tocopherol to alter biomarkers of oxidative stress in female Zucker obese rats. J. Nutr. 2003, 133, 2838-2844).
Anthocyanins belong to antioxidant polyphenols and are present in various foods and beverages. Consumption of anthocyanins is associated with reduced risk of several degenerative diseases such as atherosclerosis, cardiovascular disease, cancer and diabetes (Jayaprakasam, B.; Strasburg, G. A.; Nair, M. G. Potent lipid peroxidation inhibitors from Withania somnifera. Tetrahedron 2004, 60, 3109-3121). These compounds are well-known free radical scavengers and reported as potential chemopreventive agents (Duthie, G. G.; Duthie, S. J.; Kyle, J. A. M. Plant polyphenols in cancer and heart disease: implications as nutritional antioxidants. Nutr. Res. Rev. 2000, 13, 79-106). For example, serum antioxidant capacity was increased by the consumption of strawberries, cherries, and red wine (Kang, S. Y.; Seeram, N. P.; Nair, M. G.; Bourquin, L. D. Tart cherry anthocyanins inhibit tumor development in ApcMin mice and reduce proliferation of human colon cancer cells. Canc. Lett. 2003, 194, 13-19; Van Velden, D. P.; Mansvelt, E. P. G.; Fourie, E.; Rossouw, M.; Marais, A. D. The cardioprotective effect of wine on human blood chemistry. Ann. New York Acad. Sci. 2002, 957, 337-340; Wang, H.; Nair, M. G.; Strasburg, G. M.; Chang, Y. C.; Booren, A. M.; Gray, I. J.; DeWitt, D. L. Antioxidant and anti-inflammatory activities of anthocyanins and their aglycone, cyanidin, from tart cherries. J. Nat. Prod. 1999, 62, 294-296). Recent studies demonstrated that the anthocyanin, cyanidin 3-glucoside, reduced the high fat diet induced obesity in mice (Espin, J. C.; Soler-Rivas, C.; Wichers, H. J.; Garcia-Viguera, C. Anthocyanin-based natural colorants. A new source of antiradical activity for foodstuff. J. Agri. Food Chem. 2000, 48, 1588-1592). Therefore, the natural colorants present in the food have attracted consumers due to their safety, nutritional and therapeutic values (Millspaugh, C. F. In American Medicinal Plants; Dover Publications: New York, 1974; p 282). Since anthocyanins are widely consumed, additional biological activities of these compounds are of great interest.
Several studies suggest that diets rich in fat and low in fiber result in obesity. Obesity alters the lipid metabolism, which in turn leads to insulin resistance. Under obese conditions, the adipose tissue produces an enormous amount of free fatty acids (FFA). The FFA then inhibits the glucose uptake, glycogen synthesis and glucose oxidation (Saltiel, A. R. and Kahn, C. R. (2001) Insulin signaling and the regulation of glucose and lipid metabolism. Nature 414, 799-806) and results in hyperglycemia and type-2 diabetes. The type-2 diabetes is an increasingly common disorder and approximately 150 to 300 million people suffer worldwide and expected to double in the next 25 years (King, H., Aubert, R. E., and Herman, W. H. (1998) Global burden of diabetes, 1995-2025: prevalence, numerical estimates, and projections. Diabetes Care 21, 1414-1431). Recently, much attention has been focused on food that may be beneficial in preventing diet-induced body fat accumulation and possibly reduce the risk of diabetes and heart disease.
There are several biochemical processes involved in controlling the food intake. The glucagons-like-peptide-1 and -2 (GLP-1 & -2) were synthesized in endocrine cells and released into the blood in response to nutrients intake. The GLP-2 enhances the nutrient absorption by expanding the mucosal epithelium (Ahren, B. (1998) Glucagon-like peptide-1 (GLP-1): a gut hormone of potential interest in the treatment of diabetes. BioEssays 20, 642-651 and Drucker, D. J. (2002) Biological action and therapeutic potential of glucagons like peptides. Gastroenterology 122, 531-544). The GLP-1 is mainly expressed in gut L-cells and it inhibits glucagon secretion and gastric emptying by the liver, which in turn inhibit the food intake and stimulates insulin biosynthesis and secretion by pancreatic β-cells (Ahren, B. (1998) Glucagon-like peptide-1 (GLP-1): a gut hormone of potential interest in the treatment of diabetes. BioEssays 20, 642-651 and Drucker, D. J. (2002) Biological action and therapeutic potential of glucagons like peptides. Gastroenterology 122, 531-544). The primary function of pancreatic β-cells is to secrete the bioactive insulin, in response to nutrients, hormones and nervous stimuli, in order to keep the normal physiological glucose concentrations of the body (Rohit, N. K. (2004) The islet β-cell. The Int. J. Biochem. Cell Biol. 36, 365-371). The progressive loss of the pancreatic β-cell function in response to elevated blood glucose levels causes the insulin deficiency, which leads to type-2 diabetes. The insulin resistance, the failure of liver, muscle, and adipose tissue to respond to physiologic doses of insulin, also causes type-2 diabetes (Pinget, M., and Boullu-Sanchis, S. (2002) Physiological basis of insulin secretion abnormalities. Diabet. Met. 28 (6, Suppl.), 4S21-4S32). Both insulin deficiency and resistance lead to health problems such as hyperlipidemia, atherosclerosis and hypertension (Saltiel, A. R. and Kahn, C. R. (2001) Insulin signaling and the regulation of glucose and lipid metabolism. Nature 414, 799-806) and often linked to the impaired carbohydrate and lipid metabolism (Brosche, T. (2001) Plasmalogen levels in serum from patients with impaired carbohydrate or lipid metabolism and in elderly subjects with normal metabolic values. Arch. Gerontol. Geriatrics 32, 283-294). These control systems interact in complex pathways and any alteration by genetic, environmental and social factors causes obesity and diabetes (Ross, S. A., Gulve, E. A., and Wang, M. (2004) Chemistry and biochemistry of type 2 diabetes. Chem. Rev. 104, 1255-1282). However, some of the complications resulting from social and environmental factors may be delayed or prevented by exercise and proper diet (Christian, K. R., and Barnard, R. J. (2005) Effects of exercise and diet on chronic disease. J. Appl. Physiol. 98, 3-30). Epidemiological studies showed that diets rich in fruits and vegetables reduce the incidence of cancer, cardiovascular disease, diabetes, cataracts, and inflammatory disease (World Cancer Research Fund/American Institute for Cancer Research (1997) Food, nutrition and the prevention of cancer: A global perspective 1997, American Institute for Cancer Research Washington, D.C.; U.S. Department of Agriculture, U.S. Department of Health and Human Services (1995) Nutrition and Your Health: Dietary Guidelines for Americans 1995, U.S. Government Printing Office Washington, D.C.; American Heart Association (1996) Dietary guidelines for healthy American adults: A statement for health professionals from the nutrition committee, American Heart Association. Circulation 94, 1795-1800; American Cancer Society (1996) Guidelines on diet, nutrition, and cancer prevention: reducing the risk of cancer with healthy food choices and physical activity. Cancer J. Clin. 46, 325-341; World Health Organization (1990) Diet, Nutrition and the prevention of chronic diseases: Report of a WHO study group, Technical Report Series 797, WHO Geneva, Switzerland; Willett, W. C. (1999) Goals for nutrition in the year 2000. Cancer J. Clin. 49, 331-352 and Willett, W. C. (1998) Nutritional Epidemiology 1998, Press: Oxford University, New York, N.Y., USA).
Recently, there has been an increased interest in natural hypoglycemic compounds derived from generally regarded as safe (GRAS) plants, fruits and vegetables since they are considered to be less toxic with fewer side effects. These bioactive compounds present in the food can alter gene expression and cellular events (Milner, J. A. (2004) Molecular targets for bioactive food components. J. Nutr. 134, 2492S-2498S) resulting in the modification of proteins and their functions. Although several studies suggested that the phytochemicals present in the fruits and vegetables are beneficial to ameliorate adverse health risks, their anecdotal protective effects have not been well understood.
The Cornus fruits are used in anti-diabetic traditional Chinese prescription medicines such as “Hachimi-Gan” (Yamahara, J.; Mibu, H.; Sawada, T.; Fujimura, H.; Takino, S.; Yoshikawa, M.; Kitagawa, I. Biologically active principles of crude drugs. Anti-diabetic principles of corni fructus in experimental diabetes induced by streptozotocin. Yakugaku Zasshi 1981, 101, 86-90). We have recently reported the quantification of anthocyanins in Cornus spp. fruits (Seeram, N. P.; Schutzki, R.; Chandra, A.; Nair, M. G. Characterization, Quantification, and Bioactivities of Anthocyanins in Cornus Species. J. Agri. Food Chem. 2002, 50, 2519-2523).
The fruits of the Cornus species are a rich source of anthocyanins. The fruits of Cornus mas L., also known as the European and Asiatic Cornelian cherry, are used in the preparation of beverages in Europe (Kim, D. K.; Kwak, J. H. A Furan derivative from Cornus officinalis. Arch. Pharm. Res. 1998, 21, 787-789). In traditional medicine, Cornus officinalis fruits are known for their analgesic and diuretic activities (Yamahara, J.; Mibu, H.; Sawada, T.; Fujimura, H.; Takino, S.; Yoshikawa, M.; Kitagawa, I. Biologically active principles of crude drugs. Anti-diabetic principles of corni fructus in experimental diabetes induced by streptozotocin. Yakugaku Zasshi 1981, 101, 86-90). The Cornus fruits are also one of the major constituents of several anti-diabetic herbal preparations in Asian countries (Seeram, N. P.; Schutzki, R.; Chandra, A.; Nair, M. G. Characterization, Quantification, and Bioactivities of Anthocyanins in Cornus Species. J. Agri. Food Chem. 2002, 50, 2519-2523). Earlier investigation of the fruits of C. mas and C. officinalis revealed that both contained high levels of anthocyanins (Beckwith, A. G.; Zhang, Y.; Seeram, N. P.; Cameron, A. C.; Nair, M. G. Relationship of Light Quantity and Anthocyanin Production in Pennisetum setaceum Cvs. Rubrum and Red Riding Hood. J. Agric. Food Chem. 2004, 52, 456-461).
The C. mas plant yields fruits similar to tart cherry (P. cerasus). It belongs to the family Cornaceae and is a deciduous tree native to Europe and western Asia (Millspaugh, C. F. American Medicinal Plants; Dover Publications: New York, 1974; p 282). The fruits of this species have been used in Turkey to make several concoctions. Earlier studies demonstrated that the alcoholic extract of Cornus officinalis increased the GLUT 4 mRNA expression, a glucose transporter, in non-insulin dependent diabetes mellitus (NIDDM) rats (Qian, D., Zhu, Y., and Zhu, Q. (2001) Effect of alcohol extract of Cornus officinalis Sieb. et Zucc on GLUT4 expression in skeletal muscle in type 2 (non-insulin-dependent) diabetes mellitus rats. Zhongguo Zhongyao Zazhi 26, 859-862). The Cornus fruits are well known in the Chinese medicine as well and the fruits of this species are used to cure diabetes in China. However, the active compounds that are responsible for the anti-diabetic activity have not been characterized. Earlier studies on fruits from several Cornus spp. grown in Michigan revealed that C. mas contained high levels of anthocyanins (Seeram, N. P., Schutzki, R., Chandra, A., and Nair, M. G. (2002) Characterization, quantification, and bioactivities of anthocyanins in Cornus species. J. Agric. Food Chem. 50, 2519-2523).